Tabris.js Call Detection Plugin

A Tabris.js plugin that reports whether a phone call is currently active on the device. No UI, no runtime permissions.

if (callDetection.inCall) {
  // a call is ringing, being dialed or connected
}

Status

Platform	Signal	Permission	State
Android	AudioManager.getMode() in MODE_RINGTONE, MODE_IN_CALL, MODE_IN_COMMUNICATION (plus the call-screening and redirect modes)	none	implemented, verified on the emulator
iOS	CXCallObserver.calls containing a call that has not ended	none	implemented; compiles and runs on the Simulator, real-call test on a device pending

What the Android signal means

Telecom switches the device audio mode while a cellular call rings, is dialed or is connected, and VoIP apps that integrate with Telecom or set the communication mode do the same. Reading the mode requires no permission and no Play Store data-safety disclosure. It is a strong risk signal, not proof:

• It can not tell who is calling, or distinguish a fraud call from a legitimate one.
• VoIP apps that neither use Telecom nor set MODE_IN_COMMUNICATION are invisible.
• Any app that sets MODE_IN_COMMUNICATION (voice assistants, recorders) reads as a call.
• Outgoing calls read as active from the moment they are dialed.

What the iOS signal means

CallKit reports every call the system knows about, without permission and without exposing who is calling: cellular calls and VoIP calls of apps that integrate with CallKit (FaceTime, WhatsApp and most others). A call counts from dialing or ringing until it has ended.

• VoIP apps that do not use CallKit are invisible.
• With Live Voicemail enabled (iOS 17+), a declined incoming call may still count as active until the caller hangs up.
• The Simulator has no calls; inCall is always false there.
• Apple documents CXCallObserver for observing the system's calls; it is widely used for this purpose, but there is no API contract that other apps' calls will always be reported.

Usage

Add the plugin to your app's cordova/config.xml:

<plugin name="tabris-plugin-call-detection" spec="<git url or version>" />

The plugin registers the global singleton callDetection. TypeScript typings are included; reference them via the package's types entry.

API

Member	Type	Description
callDetection.inCall	boolean, readonly	true while a call is active. Every read queries the native side.

The object can not be disposed.

Development

Android

project/android is an Android Studio / Gradle project that compiles src/android against the Tabris.js client library of a locally installed Tabris.js Android platform:

export TABRIS_ANDROID_PLATFORM=~/.tabris-cli/platforms/android/<version>
cd project/android && ./gradlew :call-detection:assembleDebug

iOS

The Objective-C sources in src/ios are compiled as part of the app build (tabris build ios); there is no separate Xcode project. Xcode 14.3.1 (iOS 16.4 SDK) is sufficient to build and run the example on the Simulator:

cd example && npm install && tabris build ios --debug --emulator
xcrun simctl install booted "build/cordova/platforms/ios/build/emulator/Call Detection Plugin Example for Tabris.js.app"
xcrun simctl launch booted com.eclipsesource.tabris.calldetection.example

If your npm is configured for the old npm.tabrisjs.com mirror, prefix the build with npm_config_registry=https://registry.npmjs.org/: the mirror serves tarballs whose checksums do not match package-lock.json.

Example app

example/ is a Tabris.js app consuming the plugin from the parent directory (spec="../", packed by a before_platform_add hook because Cordova can not consume a plugin from a parent folder directly):

cd example && npm install && tabris run android

Testing calls on the emulator

The emulator's virtual GSM modem drives Telecom exactly like a real radio, so the audio mode switches the same way. With the example app running in the foreground:

example/scripts/android-call-test.sh            # incoming + outgoing call, prints inCall vs. audio mode

Start the emulator with -no-audio unless you want to hear it ring. MODE_IN_COMMUNICATION (VoIP) can not be simulated on the emulator; test it with a real device and a VoIP app.

After changing anything in the plugin, run tabris clean first: an incremental build reuses the existing Cordova project and silently ends up without the plugin (callDetection is not defined). Use TABRIS_ANDROID_PLATFORM=<path> to build against a locally installed platform without a download.

License

Revised BSD License (3-clause license), see LICENSE.